Bedfordshire school supports steel trees

Steel trees supporting a series of atrium roof lights are the standout design feature of a new school being built on land formerly occupied by Cranfield University’s agricultural campus in Bedfordshire.

Silsoe Church of England Lower School near Bedford is a steel-framed structure divided in half by a 50m-long central atrium that runs down the spine of the school, allowing access from the main entrance to most areas of the school.

The atrium also provides break-out spaces and informal teaching areas beneath a series of steel trees that symbolise an outdoor park landscape and form an integral element of the school’s faith-based design.

Working on behalf of main contractor Ashe Construction, SDM Fabrication has erected 118t of steel for the entire project.

SDM Director Richard Melton said: “As far as the steel construction was concerned the biggest challenge was the complex fabrication of the five steel trees as each one is bespoke and required a lot of intricate design work.”

Manufactured from CHS sections, each tree is formed from a main tubular trunk and three smaller CHS structural tubular branches.

The branches have been designed aesthetically to not only provide the structural support for the atrium’s roof lights, but also to give the atrium the feel of a woodland walk. The circular roof lights placed at the top of the “trees” allow light to flood down into the space below.

As the atrium slopes from a double-height space down to a single storey high zone, so correspondingly each tree has a different height with the tallest standing at 6.85m.

The trees were manufactured and assembled at SDM’s facility and delivered to site complete with the four structural branches already welded in place.

“Once they were erected on site we welded a further five tubular branches to each individual tree,” added Mr Melton. “These are purely architectural as they don’t support the roof but they do make the trees look a little more realistic.”

As a finishing touch and to add a little more to the outdoor feel, the tree steelwork will be painted green and brown, while astro turf will be installed around the bases of the trees.